A parking lot at the edge of the woods, empty except for a single car. Inside, a mother of two, murdered in cold blood.

Police say she was taken by surprise and the killer could be someone she knew.

Crime Watch Daily investigates a cold case that's suddenly red hot.

We reveal shocking new evidence to a family begging for answers and ask the gut-wrenching question: Was Sandy Long murdered by one of their own?

"She's probably one of the most beautiful things that happened to me in my life," Louis Long tells Crime Watch Daily.

Louis isn't the only one. His wife, Sandra Long, is the light of so many lives.

"Funny, loved to cook, fun to be around, loved to dance. Spunky person," said Louis.

A wife, a mother of two teen girls, Sandy was the center of a big joyful family that spends every spare minute together in Lusby, Maryland. And nothing makes Sandy happier than her kitchen filled with friends and family.

"She was a great cook. We grew up together in the same neighborhood, so we had the opportunity to spend so much time with each other," said Sandy's cousin Tisa Crowner.

The churchgoing mom was generous at home and work, where she drove people with disabilities to and from their jobs.

"She was a giving person. She would literally take her last and give it to you," said Sandy's sister DeLois Johnson. "She was just a kind soul."

And on the drizzly morning of November 30, 2010, that kind soul was taken away forever. That day Sandy woke up early to pick up one of her disabled clients. Sandy's aunt Annie Chase lives just next door and waves goodbye. She says Sandy seemed in good spirits. But something about that morning gives Annie Chase a chill.

"I stood here and watched her until she got out of sight up there. I kept saying 'There's something funny,' something kept dawning on me something was funny," Chase tells Crime Watch Daily.

Annie's premonition is eerily on the money. Hours later, Sandy's client calls in to say Sandy didn't pick him up. When Sandy's husband Louis Long hears that, he races home from work.

"She never did that before, that's not in her character. If she wasn't going to work or she had changed her mind, she would've called me," Louis tells Crime Watch Daily.

Louis and the family gather at his house wondering where on Earth could Sandy Long be?

"We was concerned, she was just always prompt and on time," said cousin Tisa Crowner.

Minutes stretch to hours with no word at all. Then Sandy is found. At 2:30 p.m., Hunters pull in next to a car in a dirt lot near Calvert Cliffs State Park. The hunters notice a woman inside the car with one foot in the air lying across the front seat. At first they think she's sleeping. Then they see blood.

It's Sandy Long. The beloved wife and mom has been brutally stabbed to death.

"There was blood on the floor, in a cup holder. She was stabbed several times, so there definitely is going to be blood," said Maryland State Police Sgt. David Sexton.

Sgt. Sexton tracks Sandy Long's timeline, and right from the start, the pieces just aren't adding up. When Sandy left home, she was alone. Less than two miles away, Sandy was found dead. Somewhere in between, Sandy's attacker got into her car. Police say maybe Sandy knew her killer and maybe that person was on the side of the road and needed some sort of help, and she picked that person up on her way to work.

"Wholeheartedly I believe that she knew her attacker," said Sgt. Sexton.

Sandy's family agrees she would never let just anybody into her car.

"Sandy had to pick someone up that she knew, and she knew very well," said Annie Chase, Sandy's aunt.

Sandy's valuables were untouched.

"Her purse was in the car, was in the trunk," said Sgt. Sexton. "There was no sign of any kind of robbery or anything, so I think it was definitely somebody that she knew."

And Sexton believes the killer wanted Sandy's body to be discovered.

"Wasn't like they took her to the woods and dug some kind of shallow grave or dumped her in a river or something like that. They wanted her to be found," said Sexton.

But who could possibly want this sweet woman dead?

Louis Long says he was at work and has repeatedly insisted that he has no reason to kill his wife. He was questioned multiple times.

"I don't have nothing to hide," said Louis.

Police say Sandy's husband's alibi checks out. They say he was working at a school in Prince Frederick, Maryland at the time of his wife's disappearance and murder. He also submitted to a polygraph test and police say he passed.

"Polygraph is not a 100-percent end-all-be-all," said Sgt. Sexton. "You know, there's always a possibility that he could have paid someone or asked somebody to do this. We just haven't found that link."

Detectives widen their circle of suspicion. And some provocative clues came from Sandy Long herself.

"That Sunday I went to church and she was there," said Sandy's sister DeLois Johnson. "It was an emotional service that day, and I remember the tears that I saw, and I didn't know what those tears may have been. But two days later, she was murdered."

Beloved mom from Sandy Long was found stabbed to death in her car less than two miles from home, in November 2010 Maryland State Police Sgt. David Sexton is sure the killer was someone Sandy knew.

"She would have never picked up a hitch-hiker. She wasn't like that," said Sgt. Sexton. "And I don't think it was a stranger that did this."

If not a stranger, then who? Police began their search right at Sandy's doorstep with her husband Louis Long.

"People always think it's going to be the spouse or boyfriend or some kind of relationship," said Sgt. Sexton.

But it does not appear Louis Long had anything to do with this.

"Not right now, no," said Sexton.

Still, Sandy's family urges police to take a closer look at Louis.

"I was told that there was some things that was going on in the home," said Sandy's cousin Tisa Crowner.

At any point, did Louis ever hurt Sandy?

"Never. Never. Never put hands on Sandy, never. Mentally, when we get in a fuss we can say some hurtful things, I will say that, but as far as physically putting hands on her, no. Uh-uh." said Louis.

Not on Sandy -- but police discover Louis was accused of putting his hands on Sandy's daughter, Louis's stepdaughter Keana. She told Crime Watch Daily me it was a one-time thing.

"He entered my room, and he touched my butt and I believe he started to like touch like the front of me, and then I just like backed up, I believe I even like jumped on the bed to like try to get around him, and I ran out of the room," Sandy's daughter Keana Harrod tells Crime Watch Daily. "Just that one time."

"She was dealing with some things in her life, and when you're dealing with certain things in your life, problems come, things being said," said Louis.

What Keana did say causes a lot of family turmoil. The allegations of inappropriate contact from Louis that Louis denies, are never proven, but lead to a physical argument.

"There was an assault between Louis, her husband, and his stepdaughter Keana at some point that almost went to court. It didn't go to court," said Sgt. Sexton.

Police say the case was dropped because Sandy took Louis's side over her own daughter.

"I think Keana was a little upset about how her mother kind of sided with Louis at the time, trying to I guess trying to keep the family together, trying to keep both parties happy," said Sexton.

But Sandy also apparently wasn't happy with her husband for other reasons.

"A couple weeks before she wasn't acting like herself. Was she tormented by something, was she -- had she just broken up with someone?" said Sexton.

Turns out that was true.

"Her husband was a little bit controlling, was a drinker, had a lot of guys over playing cards," said Sexton.

"To me she seemed like she was just trying to make things work, that she wasn't happy," said Tisa Crowner.

That's when a startling secret comes to light: Sandy had just ended a yearlong affair. Did a scorned man take revenge on Sandy?

Louis Long tells Crime Watch Daily he didn't know Sandy had a boyfriend.

"We didn't find out about him until a week after the investigation started, because nobody wanted to tell us about him, because they were afraid it would put Sandra in a bad light," said Sgt. Sexton.

When police track him down, he's eager to talk.

"He's married, so it was before his wife got home, and got all his information, we talked to his employer, got his truck that he used, had a GPS tracker, we knew he was in the D.C. area at the time, very early in the morning," said Sgt. Sexton. "So he wouldn't have had a chance to be even close to here."

The man is accommodating, and has just one request: That the secret affair remain a secret.

"He was very cooperative. I wanted to keep him cooperative, so she [his wife] never found out about it," said Sexton.

Sandy's mystery man is cleared. But there's something else Sandy may have kept concealed.

"Sandra took out the life insurance policy for her kids," said Sexton. "If something happened to her, she wasn't sure that Louis was going to take care of her kids 'cause they're not his."

The beneficiaries are Sandy's daughters and Sandy's sister Joyce.

"If anybody was going to take care of her kids, it was going to be her sister Joyce," said Sgt. Sexton.

It's something Louis Long's hearing about for the first time.

"I didn't know that neither," said Louis. "That's the first I heard of that."

As far as life insurance, did he receive anything?

"Nothing," said Louis.

Secret lovers; trouble at home; even a life insurance payout. But so far, investigators are not able to connect the dots. Then a break in the case comes right from the crime scene.

"We took a lot of people's DNA and fingerprints," said Sgt. Sexton.

And it turns out there are only two sets of DNA profiles recovered from Sandy's car.

One is Sandy's. The other points a finger shockingly close to home.

"We've checked out a lot of people," said Maryland State Police Sgt. David Sexton.

But the interviews haven't produced enough evidence to officially name any suspects since Sandy's murder in 2010.

But now, a fresh look at DNA from the crime scene might bust the case wide open.

"The DNA sample that was taken, and it's very sensitive testing now," said Sgt. Sexton. "Now you can just touch something and they can get DNA off the steering wheel or anything."

Sgt. Sexton suspects the killer stabbed Sandy to death after she left home, then dumped her car with Sandy inside. Sexton's team takes a microscope to Sandy's steering wheel.

"We still have the steering wheel cover and have that DNA tested again," said Sexton.

And from that single strip of leather they pull two sets of DNA profiles. One is Sandy's. The other belongs to a member of Sandy's own family, Sandy's brother-in-law Sammy Weems. He's married to Sandy's sister Joyce, who also happens to be one of the beneficiaries of Sandy's life insurance payout. And he lives right around the corner from Sandy's house.

"No other DNA except for Sandra's. Sandra and Sammy," said Sgt. Sexton.

The DNA doesn't connect Sammy Weems directly to the crime, but it does connect him to the car.

"Now maybe he didn't assault his sister-in-law, but maybe he knows the person that did it," said Sexton.

The match is the biggest break in the case so far. But it's not a slam-dunk. Sammy has a simple explanation: Early on he admitted to police he's been in Sandy's car before.

"He indicated that he has in the past had to back her car out of the driveway," said Sexton.

But then the state forensics lab counters with this:

"They seemed to think it was a little more than just getting in the car and backing it out and getting out. It was more time in the car, sweating more profusely maybe," said Sexton.

After initially providing his DNA to investigators, Sammy Weems goes silent.

"His wife took a polygraph, very cooperative. After his wife came in I wanted him to come in to talk more about the investigation, and he was not cooperative," said Sgt. Sexton.

Sexton also wants to talk to Sammy's brother. He happens to live on the same road Sandy took that fateful morning.

"On the Weems side there were a couple that weren't cooperative," said Sexton. "I don't know if that was because they had problems with police or they just know something and they didn't want to be involved."

Sammy Weems has not been named a suspect in the murder, or even a person of interest. But that doesn't mean that police don't want to check in with him again.

"Most of the family members know that he may have used her car and that his DNA was in the car. Not all the family members know that, but some do, some know," said Sgt. Sexton. "I think it's family members that know what happened."

Crime Watch Daily gathered 13 of Sandy's relatives together: sisters, cousins, nieces and godchildren. Some know DNA was found in the car, but don't know it's from someone they call family.

Suddenly it becomes a very uncomfortable in this room full of family. Before we go any further, to protect the younger members of Sandy's family, they are asked to leave the room. Then we move forward with adults only. But suddenly Sandy's niece Glenda Johnson stops me again.

"I'm not quite sure if I feel comfortable with everyone else knowing," Johnson says.

So the folks who maybe don't know what's being discussed are asked to leave the room. Now only two people are left: Sandy's cousin Tisa Crowner and Sandy's niece Glenda Johnson. They know it was Sammy Weems' DNA that was found in Sandy's car.

"Since the day that Sergeant Sexton told us, gave us that information, I don't know what to think. I don't know what to feel about that," said Glenda. "Every part of me is 'No that can't possibly be,' there is no way that can be true."

Sammy Weems hasn't been named a suspect or a person of interest. But Sgt. David Sexton still hopes he can assist in their investigation.

"I would love to sit down and talk to him again and just clear the air," said Sgt. Sexton.

Weems helped at first, but now he's telling the cops to get lost.

"Maybe he has some information for us that that we can use," said Sexton.

Crime Watch Daily went looking for Sammy Weems and tried to reach him a number of times. We located him in a grocery store parking lot. Sammy says he feels he's helped all he can in the investigation. He tells us he gave his palm print and DNA to investigators, but declined to take a polygraph test.

"I would take one," says Weems. "But I gave my palm print, DNA. Why they keep bothering my family? My family -- because she was found at the hunting range, that don't have anything to do with Camp Canoy [Road]."

Sgt. Sexton said Sammy Weems' DNA had been found in the car.

"Yeah, I took the car to the store before, yeah," says Weems.

Would Weems be willing to be a part of more interviews as part of Sexton's investigation?

"No, I'm not being a part of nothing, 'cause Sexton came to my family's house like 20 or 30 times, or 40 times, causing misunderstandings, starting arguments in the yard with my brother, I mean everything," says Weems. "My brother told him stick it up his [---], I'm saying it too, stick it up his [---]. We don't know."

And Weems has even stronger words for his sister-in-law's grieving family. Some of Sandy's relatives point the finger at Sammy Weems, and he makes these outrageous, unfounded allegations against them.

"You know, these people are sick. This family's sick. I'm sorry what happened to Sandy, but this family is a sick group of people," says Weems. "They've got a history of having sex with other family members, having kids and marrying each other, family members. This family is a sick group of people, and they're trying to blame people for their guilt and their trashiness."

And Sammy Weems says the key to solving Sandy's murder lies with her husband Louis Long and her daughter Keana.

"I think he knows something," says Weems. "But I don't know, I mean, I think he knows something, but you know, you gotta talk to Louis and his daughter. You gotta talk to them two."

So we asked Louis Long if he feels like people in the community view him as the killer.

"Yes, absolutely," Louis tells Crime Watch Daily. "But my closet is full of hate, I don't want to put no more in it, so I'm learning how to block things out. That's the best way I could tell you."

Are you the killer?

"No ma'am," said Louis. "I did all I can for my, to prove my innocence. As long as I live it's always gonna be that doubt. I can't defend everything people say about me."

Did you hire anyone to kill Sandy?

"No. No."

We also spoke to Sandy's oldest daughter Keana Harrod by phone, and she makes a startling revelation, saying the heat has been on her too.

In the summer of 2016, Sgt. Sexton calls Keana and says he needs her to come in for a polygraph, which she did. Keana splits Sandy's $50,000 life insurance policy with her younger sister, but tells Sexton she had nothing to do with her mom's murder. That's when the sergeant responds with the jaw-dropping results of her lie-detector test.

"He was like, 'So, you didn't pass your polygraph,'" Keana tells Crime Watch Daily. "At some point he pulled this chair up and we're like knee to knee, and he's just in my face and he's you know saying 'You slit your mom's throat.' Whatever happened to her he was telling me I did that to her, and again, in total shock, and I'm just like 'Sgt. Sexton,' I'm like, 'Are you serious right now?' I was like 'You can't be kidding me.'

"Honestly, I mean, I am hurt," said Keana. "For someone to accuse me of doing something so tragically to someone I love so much, like I would never in my life, never, never. Every day I am just like, Why?"

With Sandy Long's vicious murder still unsolved after seven long years, "why" is a question asked by her entire heartbroken family every day.

"If you know something say it, tell somebody, get it off your chest," said Patricia Harrod. "How can you just sit there and sleep at night? How can you even do anything?"

"It's hard to understand why someone want to do that. She was so caring and so loving. I said 'Lord, thank you for blessing me to have her in my life.' I truly miss her," said Sandy's cousin Cleo Parker.

Police say they're closer than ever to bringing Sandy Long's killer to justice.

If you have any information about the murder of Sandy Long, contact Calvert County Crime Solvers at (410) 535-2880. There's a $5,300 reward.